There is a conventional input system that gives a feel to a user to make the user recognize that the input system has received a user's operation onto an operation surface of a panel. In regard to the input system, there has been proposed a technology for generating a click feel by vibrating a vibration element at a voltage having a waveform obtained by applying an envelope to a sine wave when the operation surface of the panel is manipulated (see, e.g., Japanese Laid-open Patent Publication No. 2013-109429).
However, the conventional technology has room for improvement in improving an operational feeling to be given to a user when the same operational feeling as an operational feeling onto a mechanical switch is given to the user.